166 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Oxytricha pellionella Mull. 



Body elastic but persistent in form, more than four times as long as 

 broad, slightly widest centrally and tapering to each end. Extremities 

 equally rounded. Peristome narrowly triangular, relatively short. Three 

 large hooked frontal styles, and three small straight ones; five scattered 

 ventral styles; five long anal styles, projecting beyond the posterior margin 

 of the body; an uninterrupted series of marginal setae. Two macronuclei 

 and two micronuelei. Contractile vacuole located near the middle of the 

 left-hand border. 



Found in an infusion of hay and leaves. 



Sizes range from 86 to 160 microns. Length of type specimen, 160 

 microns. (Fig. 46, plate XLI1I.) 



Genus Stylonychia Ehr. 



Body persistent in form, inflexible, elongated or elliptical. Dorsal sur- 

 face convex, ventral surface flat. Eight frontal, five ventral, and five anal 

 styles; three long, hair-like caudal setae. Marginal setae forming a con- 

 tinuous border on each side of the body. Two macronuclei. Contractile 

 vacuole single, located on the left-hand side of the body, near the posterior 

 angle of the peristome. 



Stylonychia mytilus Ehr. 



Body elongated oval, more than twice as long as broad, widest anteriorly 

 and tapering to the posterior end. Posterior third of the body often quite 

 narrow and curved. Both extremities rounded. Peristome large, broadly 

 triangular, its reflected border with an undulating membrane. The two 

 right-hand anal styles projecting beyond the posterior extremity of the 

 body; caudal setae long, slender, and widely separated, interrupting the 

 marginal series. 



Found in pond water. 



Sizes given vary from 90 to 400 microns. Length of type specimen, 160 

 microns. (Fig. 43, plate XLIII.) 



Stylonychia pustulata Ehr. 



Body elongated oval, about twice as long as broad, rounded at the ex- 

 tremities, not tapering. Caudal setae short, close together, scarcely in- 

 terrupting the marginal series; most of the anal styles projecting beyond 

 the posterior border. Two macronuclei and two micronuelei. 



Found in vegetable infusions. 



Lengths given vary from 90 to 170 microns. Length of type specimen, 

 105 microns. (Fig. 42, plate XLIII.) 



Stylonychia notrophora Stokes. 



Body elongated, elliptical. Left side of anterior margin obliquely 

 truncated; posterior extremity rounded. Peristome broadly triangular, 

 extending to near the middle of the body. Two or three of the anal styles 

 project beyond the margin of the body; caudal setae long, slender and 

 widely separated. Two macronuclei and two micronuelei. 



Length of type specimen, 115 microns. (Fig. 44, plate XLIII.) 



